Etiology and pathophysiology of AML

Etiology and risk factors of AML

Like many kinds of cancers, the etiology for most cases of AML is unclear, and currently there is no known major cause of AML. However, there are multiple risk factors that are associated with AML. Generally, known risk factors account for only a small number of observed cases. These risk factors are explained and listed below.

Smoking is the only proven lifestyle-related risk factor for AML. It is known that smoking is linked to multiple types of cancer, specifically lung, mouth, throat and larynx cancers, but few people realize that smoking affects cells that don’t come into direct contact with tobacco. The tobacco that is absorbed by the lungs can spread into the bloodstream to many parts and cells of the body.

Genetic disorders and constitutional genetic defects are important risk factors associated with AML. For example, children with Down syndrome have a 10-fold to 20-fold increased likelihood of developing acute leukemia.

Certain chemical exposures increases the risk of developing AML. Long-term exposure to high levels of benzene, a solvent used in oil and gasoline-related industries, rubber industries, and chemical plants.

Certain chemotherapy drugs can also increase the risk of developing AML. Many patients are diagnosed with secondary AML, which is often developed after receiving chemotherapy for separate cancers different from AML.

Radiation exposure in high doses, such as being exposed to nuclear reactor accidents or atomic bombs increases the risk of developing cancer. Radiation treatment for cancer has also been linked to an increased risk in developing AML.

Certain blood disorders and myelodysplastic syndrome (MDS) are also linked to the development of AML. The blood disorders include chronic myeloproliferative disorders such as polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis. Sometimes treatment of these disoders include radiation or chemotherapy, which further increases the risk of developing AML. Patients with MDS have low blood cell counts and abnormal cells in the blood and bone marrow, which can evolve overtime into AML.

Family history and having a close relative, such as a parent or sibling with AML increases your risk of developing AML. However, most cases of AML are not thought to have a strong genetic link.

Older age is considered to be more common in diagnoses of AML, although AML can even be diagnosed in childhood.

Male gender has been found to be more of a risk factor than female gender, even though the cause of this is unclear.

Disease progression and morbidity of AML

The word “acute” in acute myeloid leukemia denotes to the disease’s rapid progression. As discussed in the first blog post, myeloid leukemia involved the myeloid cells in white blood cells located in the bone marrow. When these cells are abnormal and fail to develop into proper mature white blood cells, patients’ immune systems are incredibly compromised, and regular colds or preventable illnesses become serious fast. Pneumonias can be fatal in patients with AML.

Sources

1. Deschler, B., & Lubbert, M. (2006, October 1). Acute myeloid leukemia: Epidemiology and etiology. Retrieved from http://onlinelibrary.wiley.com/doi/10.1002/cncr.22233/full

2. American Cancer Society. (2014, December 1). What are the risk factors for acute myeloid leukemia?